Anatomy - Connective tissue and BONES Flashcards
What are connective tissues made of ?
(6)
expand upon the 3 points
1) cells-fixed or wandering ie: fibroblast , mesenchymal , reticular cells, adipocytes, macrophages , WBCs and mast cells
2) Fibres - elastic , collagen or Reticular - MAKES EXTRACELLULAR MATRIX
3) Ground substance ( highly hydrated GEL made of : proteoglycans, glycosaminoglycans , Glycoproteins ) MAKES EXTRACELLULAR MATRIX
Explain the key function of connective tissue (5)
1- Building , packaging and transport 2-skeletal framework ( bone cartilage) 3-protection and defence 4- Transportation and nourishment 5- Repair ( scar tissue )
What are the types of Ordinary connective tissue?
(3)
where are they found?
1- Loose or areolar tissue ( low number of fibres and HIGH population of cells ). it surrounds capillaries , tubes and blood vessels
2-Dense Irregular -lots of haphazard collagen fibres , low number of cells . Found in the dermis of the skin / digestive tract .
3-Dense Regular connective tissue - lots of straight lines of collagen fibres (found in ligaments , Tendons and aponeurosis .
what are the specialised connective tissues ?
fluid (2)
supportive (2) and the sub types (5)
1) Fluid CT ie:Blood and Lymph
2) Supportive connectie tissue:
- cartilage(Hyaline, Fibrocartilage,Elastic)
- Bone ( compact and spongy )
What are the characteristics of Hyaline Cartilage ? (4) where is it found ? (4) -made of ? high content of -------- ? -contains ? -membrane ? -blood supply -properties ?
1-Type 2 collagen
2-Contains Isogenous groups (groups of chondrocytes)
3-Surrounded by perichondrium, which provides the nutrients (dense irregular cognitive tissue )
4-HIGH content of water and gas makes it a good shock absorber
5-AVASCUALR
Found in : -Trachea/Bronchi -Costal Cartilage -Nasal cavity (any articular surface for bones )
What are the characteristics for Elastic cartilage ?(5) where is it found (2) -made of -properties -vascular? -chondrocytes in---?
1-ELASTIC FIBRES 2-Type 2 collagen 3-regains shape after distortion 4-AVASCUALR hence contains a perichondrium to bring nutrients 5-chondrocytes in Lacuna Found in Pinna of the ear and epiglottis
What are the characteristics of Fibrocartilage? (4) -made of? -arrangement? -vascularisation? how will you identify in histology? -where is it found? -perichondrium?
1-Intermediatory cartilage so is a mix of both irregular, regular hyaline cartilage.
2-TYPE 1 collagen (dense irregular)
3-chondrocytes in LONG rows separated by TYPE 1 Fibre
4-AVASCULAR, nutrients arrive via diffusion through spaces
found in: Tendons, pubic symphysis, intervertebral discs
5-NO perichondrium (membrane of cartilage )
identify :
- chondrocytes in long rows
- thicker type 1 collagen fibres
- lacunae is present but smaller
- AVASCULAR
- connective tissue is less packed
- NO PERICHONDRIUM
what is the function of the following cells : a)fibroblasts b)osteoblast c)reticular cell d)mesenchymal cell e)chondroblasts (5)
a) fibroblasts secrete the extracellular matrix(fixed)
b) osteoblasts -synthesis of bones (fixed), they make the bone and get trapped becoming osteocytes which upkeep the bone tissue
c) reticular cells (fixed)- make reticular fibres (type 3 collagen)
d) mesenchymal cells- embryonic stem cell which gives rise to most connective tissue cells.
e) chondroblasts -develops cartilage , becomes trapped in cartilage to make chondrocytes ( upkeep / housekeeper)
What are the three types of fibre produced by fibroblasts? (3)
1-Collagen ( there are 25 different types )
2-Elastic Fibres
3-Reticular Fibres
how is collagen assembled ?
6
1-3 alpha polypeptide chains assemble
2- wrap around each other to from triple helix with loose ends
3-Procollagen Peptidase cleaves the loose ends and makes tropocollagen ( just collagen )
4-the collagen aligns into collagen fibril ( with 67nm GAP stagger)
5-this then forms a collagen FIBRE
6-this can then be part of a bundle
(Tropocollagen ->Fibril ->Fibre->Bundle )
describe the structure of elastic fibre (2)
1-Made of elastin AND FIBROBLASTS also produce these fibres
2-Microfibrils are made up off FIBRILIN
(MUSCLE TISSUE LIES UNDERNEATH )
Describe the structure of reticular fibres (3)
-histology ?
1- Also made of FIBROBLASTS (reticular cell fibroblast)
2-TYPE 3 collagen
3-Exist as individual reticular fibres which is found in delicate connective tissue .
they look black, dark purple with silver staining. you cant see them with H&E
describe the structure of the Ground substance
3 main points
give examples of some ground substances if you can
1- Highly hydrated cell, making up the extracellular matrix
2- made of Glycosaminoglycans (long polypeptide chain which maintains a passageway and blue print for the cell)
ie: Hyalaronic acid ( in the ECM) / Keratin sulphate in the bone cartilage/ Chondroitin sulphate ( bone, cartilage , heart valves)/Heparin sulphate ( basal lamina )
3-Proteoglycans - can make proteoglycan mega complex
4-adhesive glycoproteins
Outline the role of Osteoprogenitor cells , OsteoBLASTS, osteocytes and osteoCLASTS
1) Osteoprogeniter cells produce osteoblasts
2) OsteoBLASTS produce ECM = Builds Bones
3) Osteocytes gets trapped in lacunae and UPKEEPS the bone
4) OsteoCLASTS - carves out the bone , its responsible for rebuilding and resorption of bone.
structure of compact bone ?
6
1- lamellae (layers of bony matrix made by osteoblast) arranges in systems called HAVERSION systems( circles around canal )
2- Osteon contains:
- osteocytes in their lacunae ,
-Haversion canal which contains blood vessels and nerves;
-canaliculli ( small tributaries which connect osteocytes in their lacunae together )
-Volkmans canal connects the haversion canals together
3- 3 layers of Lamellae stack on top of one another ( collagen fibres in the same layer are all in the SAME direction , BUT each separate layer is orientated in a different direction- parallel to the layer above = strength
